Electric and plug-in electric vehicles require an interface to external charging devices. In order to promote standard interfaces among vehicle and charge station manufacturers, industry standards have been developed. One such standard is the SAE Electric Vehicle and Plug in Hybrid Electric Vehicle Conductive Charge Coupler (J1772) standard. The J1772 standard defines a charge coupler and the associated protocol required for transferring energy to the vehicle. The standard defines a common interface that all vehicle and charge station manufacturers are encouraged to follow. The standard defines the interface between the vehicle and electric vehicle supply equipment (EVSE). A vehicle connecting to a compatible EVSE should be capable of charging according to the standard.